Leading article: Top of the class

The latest issue of BBC History magazine dips its toe into the treacherous waters of ranking prime ministers. We are told that the score of each leader is based on their ability to put their visions for changing the country into practice.

It is hard to quibble with the high placement of Attlee and Thatcher. But there are a few strange appearances near the top of the list. Sir Henry Campbell Bannerman, for instance, who did little of distinction other than becoming the first prime minister to die in Downing Street (in an early example of spin his last words were: "This is not the end of me"), is judged a more effective leader than the two architects of early 20th century social reform, Herbert Henry Asquith and David Lloyd George.

The placement of Edward Heath as an equal of Winston Churchill is also an eyebrow-raiser. Significant as Heath's achievement was in taking Britain into Europe, it was surely less impressive than Churchill's defeat of Nazism on the continent.

John Major will probably feel insulted by his placement towards the bottom, below the aristocratic stop-gap Sir Alec Douglas Home and Andrew Bonar Law, "the unknown prime minister". Even historynow seems to have decided that poor Mr Major was an insignificant leader.

But William Gladstone, whose term of office falls outside the list's purview, seemed to understand the problems thrown up by such an exercise best when he said: "Former Prime Ministers are like great rafts floating untethered in a harbour." It is not easy - or necessarily advisable - to attempt to pull them into any sort of order.